Comet Cache v161221 was released on December 21st, 2016. This release includes 1 bug fix, 7 enhancements, a new Pro feature that gives Comet Cache a new Mobile Mode option, a compatibility improvement, and an improvement to the inline documentation. Notable enhancements include improved Accelerated Mobile Pages (AMP) compatibility and Widget change detection.

New Pro Feature: Mobile Mode

This releases adds a brand new feature to the Pro version: Mobile Mode. If you run a site that uses an adaptive theme, where your theme design changes based on the type of device being used to visit the site, you can use this feature to tell Comet Cache to generate separate versions of the cache so that mobile users don't see the desktop version of the site and vice versa.

Comet Cache Pro: Mobile Mode

Changelog for Comet Cache v161221

  • Bug Fix: Improving PHP OPcache detection. Now considering the INI option opcache.restrict_api. Comet Cache is now smart enough to avoid generating the PHP Warning: PHP Warning: Zend OPcache API is restricted by "restrict_api" configuration directive. See Issue #733.
  • New Feature (Pro): Mobile Mode. This release adds a new feature that is designed to improve compatibility with Adaptive themes for mobile devices. To learn more, please see: WordPress Dashboard Comet Cache Pro Plugin Options Mobile Mode. See also: Issue #471.
  • Enhancement: Auto-Clearing Author Page Cache. This release makes Comet Cache smart enough to detect when a user is deleted (or removed from a child blog in a Network), at which time the Author page for that user will be cleared from the cache so it can be regenerated automatically. See Issue #304.
  • Enhancement: Multibyte Compatibility. This release improves support for WordPress Permalinks that contain UTF-8 symbols (or emojis) in them. More specifically, this release adds the /u flag to all preg_*() calls in cache clearing routines that generate cache paths from Watered-Down Regex patterns entered by a site owner. See: Issue #611.
  • Enhancement: Widget Change Detection. Comet Cache can now detect when Appearance → Widgets are added/edited/removed, and Comet Cache will automatically clear the cache so that your site remains up-to-date. See Issue #411.
  • Enhancement (Pro): Static CDN Filters and srcset. This release enhances Static CDN Filters in Comet Cache Pro. Static CDN Filters are now smart enough to filter all image sources included in an srcset="" attribute that is generated by WordPress. See Issue #660. If you'd like to learn more about srcset="", see this article at
  • Enhancement (Pro): Automatic Background Updates. It is now possible to enable automatic background updates that occur quietly in the background whenever new features, bug fixes, or security issues are addressed by our developers. See: WordPress Dashboard Comet Cache Pro Config. Options Update Credentials. See also: Issue #827.
  • Enhancement (Pro): HTML Compressor + Accelerated Mobile Pages (AMP). Updated to the latest available release of the HTML Compressor (v161208) with improved support for Accelerated Mobile Pages. See: Issue #695. See also: HTML Compressor v161208 changelog.
  • Enhancement (Pro): HTML Compressor / AMP Compatibility. Improved compatibility with Accelerated Mobile Pages. There is a new HTML Compressor option that is enabled by default and it makes Comet Cache smart enough to auto-detect and selectively disable portions of the HTML Compressor that are incompatible with the AMP spec; i.e., routines that are not necessary when serving APMd pages. In short, if the URI being compressed ends with /amp/, or the document contains a top-level <html ⚡> tag (<html amp> is accepted as well), then features which are incompatible with Accelerated Mobile Pages will be disabled accordingly.
  • Compatibility: Avoid deprecated wp_get_sites() and use get_sites() instead. See Issue #848.
  • Documentation: Added Watered-Down Regex documentation notes to the inline documentation (in the software) about the use of ^ and $ in some places where these special characters are not fully supported. Also adding the same notes to the Watered-Down Regex KB Article. See also: Issue #611.

Props to everyone who helped with this release, including @rudrastays, @isaumya, @codesman, @lkraav, @omriamos, @Li-An, @renzms, @jaswsinc, @kristineds, @raamdev, and our 179 Beta Testers!

Upgrading to the Latest Version

Comet Cache Lite users should receive an update notification from within their WordPress Dashboard (WordPress Dashboard → Updates).

Comet Cache Pro users who have configured the Plugin Updater (WordPress Dashboard → Comet Cache → Plugin Updater) should receive a notification to upgrade on the WordPress Dashboard. If you have not configured the Plugin Updater, you can download the latest version of Comet Cache Pro by logging into your account here.

Please report bugs and feedback on GitHub. If you are a Comet Cache Pro user and require priority support, please open a support ticket here.